[RFC PATCH v3 4/4] arm64:numa: adding numa support for arm64 platforms.

Arnd Bergmann
2015-01-06T19:59:04Z

On Tuesday 06 January 2015 14:55:53 Ganapatrao Kulkarni wrote:
> On Sat, Jan 3, 2015 at 2:40 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> >> +int dt_get_cpu_node_id(int cpu)
> >> +{
> >> + struct device_node *dn = NULL;
> >> +
> >> + while ((dn = of_find_node_by_type(dn, "cpu"))) {
> >> + const u32 *cell;
> >> + u64 hwid;
> >> +
> >> + /*
> >> + * A cpu node with missing "reg" property is
> >> + * considered invalid to build a cpu_logical_map
> >> + * entry.
> >> + */
> >> + cell = of_get_property(dn, "reg", NULL);
> >> + if (!cell) {
> >> + pr_err("%s: missing reg property\n", dn->full_name);
> >> + return default_nid;
> >> + }
> >> + hwid = of_read_number(cell, of_n_addr_cells(dn));
> >> +
> >> + if (cpu_logical_map(cpu) == hwid)
> >> + return of_node_to_nid_single(dn);
> >> + }
> >> + return NUMA_NO_NODE;
> >> +}
> >> +EXPORT_SYMBOL(dt_get_cpu_node_id);
> >
> > Maybe just expose a function to the device node for a CPU ID here, and
> > expect callers to use of_node_to_nid?
> shall i make this wrapper function in dt_numa.c, which will use
> functions _of_node_to_nid and _of_cpu_to_node(cpu)

Yes, I guess that would work.

> And, this function can be a weak function in numa.c which returns 0.

No, please don't use weak functions. You can either use IS_ENABLED()
tricks to remove function calls at compile-time, or in the header
file provide an inline function as an alternative to the extern
declaration, based on a configuration symbol.

Arnd